Fluxoid jump coupled high critical current density of nano-Co₃O₄doped MgB₂

Abstract

Polycrystalline MgB 2 samples with 0, 2, 4 and 6% added nano-Co 3 O 4 being synthesized by vacuum (10 -5 Torr) annealing at 750 0 C for three hours each are found to be nearly single phase with presence of only a small quantity of Mg/MgO in pristine sample and in addition the

Synthesis and Characterization of Carbon-Doped MgB2 Superconductor Under Inert Carbon Environment

“…But the extent of diamagnetic signal is too weak in FC plots as compared to ZFC plots. This suggests the trapping of a substantial amount of flux in the samples, thereby decreasing the [38]. This is in agreement with the XRD result showing the presence of phases other than MgB 2 taking part in the formation of SNS or SIS junctions in the sample.…”

Synthesis of MgB2 superconductor under carbon induced virtual inert atmosphere

“…The FC plot showed a transition at the temperature same as that in case of zero field cooled case, thus again confirming the superconductivity in the sample. It is well known that for the highly pinned samples FC transition is quite weak as is observed in case of our sample [54]. The observation of PME indicates a strong pinning in the samples as is known due to formation of superconductor normal superconductor (SNS)/superconductor insulator superconductor (SIS) type of structures at micron level [53,55].…”

Flux pinning and inhomogeneity in magnetic nanoparticle doped MgB2/Fe wires

“…Recently, there has been considerable interest in improvement of flux pinning in MgB 2 by the use of magnetic nanoparticle additions. Although most publications report enhancement of in-field J c and B irr [6,7,8,9] upon doping of MgB 2 with magnetic nanoparticles, the actual situation is not so clear. In particular, there are some observations of detrimental influence of magnetic nanoparticles on J c of MgB 2 [10,11] and also direct, transport J c measurements on MgB 2 wires doped with magnetic nanoparticles are still lacking.…”